Data Analytics & AI | SQL Interviews | Power BI Resources
🔓Explore the fascinating world of Data Analytics & Artificial Intelligence 💻 Best AI tools, free resources, and expert advice to land your dream tech job. Admin: @coderfun Buy ads: https://telega.io/c/Data_Visual
显示更多📈 Telegram 频道 Data Analytics & AI | SQL Interviews | Power BI Resources 的分析概览
频道 Data Analytics & AI | SQL Interviews | Power BI Resources (@data_visual) 英语 语言赛道中的 是活跃参与者。目前社区聚集了 27 206 名订阅者,在 教育 类别中位列第 7 213,并在 印度 地区排名第 15 999 位。
📊 受众指标与增长动态
自 невідомо 创建以来,项目保持高速增长,吸引了 27 206 名订阅者。
根据 13 六月, 2026 的最新数据,频道保持稳定运转。过去 30 天订阅人数变化为 226,过去 24 小时变化为 5,整体触达仍然可观。
- 认证状态: 未认证
- 互动率 (ER): 平均受众互动率为 3.99%。内容发布后 24 小时内通常能获得 N/A% 的反应,占订阅者总量。
- 帖子覆盖: 每篇帖子平均可获得 0 次浏览,首日通常累积 0 次浏览。
- 互动与反馈: 受众积极参与,单帖平均反应数为 0。
- 主题关注点: 内容集中在 |--, sql, learning, analytic, visualization 等核心主题上。
📝 描述与内容策略
作者将该频道定位为表达主观观点的平台:
“🔓Explore the fascinating world of Data Analytics & Artificial Intelligence
💻 Best AI tools, free resources, and expert advice to land your dream tech job.
Admin: @coderfun
Buy ads: https://telega.io/c/Data_Visual”
凭借高频更新(最新数据采集于 14 六月, 2026),频道始终保持新鲜度与高覆盖。分析显示受众积极互动,使其成为 教育 类别中的关键影响点。
CASE statement to handle NULL values, use COALESCE():
SELECT COALESCE(name, 'Unknown') FROM users;
This returns the first non-null value in the list.
2️⃣ Generate Sequential Numbers Without a Table
Need a sequence of numbers but don’t have a numbers table? Use GENERATE_SERIES (PostgreSQL) or WITH RECURSIVE (MySQL 8+):
SELECT generate_series(1, 10);
3️⃣ Find Duplicates Quickly
Easily identify duplicate values with GROUP BY and HAVING:
SELECT email, COUNT(*)
FROM users
GROUP BY email
HAVING COUNT(*) > 1;
4️⃣ Randomly Select Rows
Want a random sample of data? Use:
- PostgreSQL: ORDER BY RANDOM()
- MySQL: ORDER BY RAND()
- SQL Server: ORDER BY NEWID()
5️⃣ Pivot Data Without PIVOT (For Databases Without It)
Use CASE with SUM() to pivot data manually:
SELECT
user_id,
SUM(CASE WHEN status = 'active' THEN 1 ELSE 0 END) AS active_count,
SUM(CASE WHEN status = 'inactive' THEN 1 ELSE 0 END) AS inactive_count
FROM users
GROUP BY user_id;
6️⃣ Efficiently Get the Last Inserted ID
Instead of running a separate SELECT, use:
- MySQL: SELECT LAST_INSERT_ID();
- PostgreSQL: RETURNING id;
- SQL Server: SELECT SCOPE_IDENTITY();
Like for more ❤️👩💼: “We want to decrease user churn by 5% this quarter”We say that a user churns when she decides to stop using Uber. But why? There are different reasons why a user would stop using Uber. For example: 1. “Lyft is offering better prices for that geo” (pricing problem) 2. “Car waiting times are too long” (supply problem) 3. “The Android version of the app is very slow” (client-app performance problem) You build this list ↑ by asking the right questions to the rest of the team. You need to understand the user’s experience using the app, from HER point of view. Typically there is no single reason behind churn, but a combination of a few of these. The question is: which one should you focus on? This is when you pull out your great data science skills and EXPLORE THE DATA 🔎. You explore the data to understand how plausible each of the above explanations is. The output from this analysis is a single hypothesis you should consider further. Depending on the hypothesis, you will solve the data science problem differently. For example… Scenario 1: “Lyft Is Offering Better Prices” (Pricing Problem) One solution would be to detect/predict the segment of users who are likely to churn (possibly using an ML Model) and send personalized discounts via push notifications. To test your solution works, you will need to run an A/B test, so you will split a percentage of Uber users into 2 groups: The A group. No user in this group will receive any discount. The B group. Users from this group that the model thinks are likely to churn, will receive a price discount in their next trip. You could add more groups (e.g. C, D, E…) to test different pricing points.
In a nutshell1. Translating business problems into data science problems is the key data science skill that separates a senior from a junior data scientist. 2. Ask the right questions, list possible solutions, and explore the data to narrow down the list to one. 3. Solve this one data science problem
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